bodmas blog

The graph above shows the structure of the HTML tags that render the front page of bodmas.org. The map was generated using a Java applet, coded using the Processing programming environment, by Sala. Sala provides a key and some examples.

In the graph above, the bottom left quadrant shows a cloud of blue links contained in a tree of grey nodes themselves sprouting from a branch of grey. This bough shows the nested links lists that appears in the right hand side bar of this page (if you are using my default Kubrick derived layout and not reading this in an RSS reader). This whole bunch springs from a single green node representing the ‘sidebar’ div in the html for the Kubrick theme. Logically, any other Kubrick themed page will have a similar graph…

One of the best Processing coded applications I have seen so far.

Ric Jensen has presented a paper at a Blogs in Education conference about using Blogger based blogs to complement his delivery of a distance learning course in Blackboard.

In his ‘screencast’, Ric states that he is new to education and the tools that he is using. Ric’s take on VLE functions is interesting from the perspective of a professional person who has been introduced to teaching recently. The range of tools we use now to engage students must seem confusing without solid guidance and a strong institutional support function.

It seems to me that there are two ways of proceeding here…

• Use a blog as a ‘gateway’ to a VLE based repository of information and interaction for students
• Use a VLE that contains a blog function and make the blog function the primary interface for the students

We are looking at the first approach at our College: the blog holds reminders, key web links, and summaries of each week’s work. This material is available to anyone who knows the blog address. Students can then log-in to a VLE based course with forums and handouts that are protected from prying eyes – the students generally feel more able to interact and post material then. The point here is that the blog contains a basic summary with a few links – it does not duplicate the richer material in the VLE, so no confusion should arise in the minds of students as to which site is ‘authoritative’ on assignment and assessment issues. Most of my colleagues are using the VLE as a filing cabinet to store handouts and guides, but some are venturing into activities that require the students to post summaries of research topics and so on.

The second approach has the students logging in first then finding a blog item about a topic, with the ability to add comments and possibly do ‘guest’ posts. This would result in a strong focus around that week’s topic – blog comments operate almost like a non threaded or linear discussion where the tutor starts the topic and students can comment. I have used linear discussion forums (like Discus) and I have found that topics stay on target more than they do with threaded mode discussions. Add to this the ability for students to upload attachments with the comments and I think you might have a useful course structure.

Any views…? I’m opening comments on this one (rare on Bodmas!!). I use comment moderation, so your comments won’t become public immediately, although you will be able to see the text.

In a previous post about a spreadsheet to show the superposition of two sine waves I used the ‘forms’ toolbar in MS Excel to produce a draggable phase angle slider. The graph of the two sine waves did not update dynamically as I moved the slider control.

Andrea J of www.allaboutoffice.co.uk has provided a VBA version of the phase angle spreadsheet that updates in real time as you drag the slider.

I had not thought of using a VBA slider control, and now I know that the VBA controls update dynamically, I’ll do more of these. Tip of the hat to Andrea and her colleagues.

Last minute favorites for the non-calculator Module 5 paper on Monday: my guess is that the following old chestnuts will appear among others… links go to BBC Bitesize and S-cool

• Circle theorems
• Loci (scale diagrams with compasses and ruler)
• Bearings
• Transformations
• All kinds of algebra

But the examiners can ask what they like!

I’ve just taken delivery of an Olympus WS-200S Digital Voice Recorder to replace my ancient cassette (yes, tape) recorder that now can’t quite generate enough torque to play a cassette..

As you can see from the snap above, the Olympus recorder itself is tiny and is dwarfed by the external microphone jack, let alone the microphone itself! The external microphone, even the cheap dynamic microphone shown above (Dixons in the UK used to sell these for about a tenner), provides a considerable quality boost over the internal microphones. The signal level from the dynamic microphone is suprisingly high to the extent that I can use the lower gain setting and reduce the hiss somewhat. The input impedance of the WS-200S preamp is given as 2Kohm so I suppose the mismatch from the 600 ohm impedance of the microphone isn’t that great.

Listen to these two samples (just under 2 minutes each)...

• Recording from the WS-200S digital voice recorder using the internal mic [810 Kb mp3 ]
• Recording from the WS-200S using a cheap dynamic microphone with the gain setting set to low [ 900 Kb MP3 ]

The overall quality with the external microphone is warmer but with a little more hiss when compared to the Logitech USB microphone fed direct into my iBook. The Olympus unit is a lot more portable however, and the AAA battery will provide 12 hours of recording. The high quality mono mode samples at 44.1 KHz and records at a bit rate of 32 Kb/s. Previous Olympus models recorded at 64Kb/s apparently so the compression is higher on these new machines.

When you have completed your recordings, you can slide the silver plastic battery unit off to reveal a usb plug – the entire recorder can just plug right into a USB socket, no need for a cable.

The Olympus voice recorders all save in Windows Media Audio (.WMA) format, which the Windows Media Player can handle – there is no software with the device. Apparently there are WMA editors available, I’ll be checking the Windows software situation over the next few weeks.

On the Mac QuickTime can play the files using the Windows Media Player plug in but you need to convert the WMA files to another format for editing. EasyWMA is a shareware ($10) application that can do the file conversion. I prefer to convert the WMA files to WAV files using easywma as WAV is an uncompressed format. I then edit the WMA files in Audacity and convert to MP3, the ‘standard’ file type for podcasts, at a 64kb/s sample rate. I’m still experimenting with this – when I tried exporting MP3s at a 32Kb/s rate there were ‘metallic’ aliasing effects in the output. The BBC use a 56Kb/s rate for their podcasts of radio talks.

Some reviews and information about the WS-200S is available, and these reviews were a factor in my decision to drop the plastic.

• Nice page with photos and some samples of sound with a good reporter’s microphone
• Olympus specifications page that gives the sampling rates
• David Battino’s comparison of three Olympus sound recorders
• Review by Andy Carvin with pictures and a sample blog

Stand by for some location based podcasts soon…

Note added 2nd June: tried a line matching transformer (500 ohm to 50Kohm) and the sound levels dropped. This might be expected from the 2000 Ohm quoted input impedance of the pre-amplifier within the WS-200S – a 50Kohm source impedance is very high compared to 2000 Ohms and will result in attenuation of the signal. This tends to go against the advice of Mindy McAdams who is using a line matching transformer with her Electro Voice reporter’s dynamic microphone. I contradict Mindy with some trepidation as she is the author of the wonderful Flash Journalism book.

• Moodle at Shefcol according to Julia Duggleby
• Blogging by me

Seb Schmoller’s fortnightly mailing is now published by typepad. Seb is inviting guest contributions, and I was honoured to be asked to contribute. I wrote about using blogger as a way of getting colleagues interested in online support. My contribution meshed in with Julia’s about the next phase – using a VLE to provide richer support.

“Some lecture classes have 250 students, so I question the effectiveness of a didactic lecture for an hour.”

Dr Bill Ashraf will be distributing lectures by podcast soon in place of live lectures in a theatre. In groups of 250 plus I can see his point: no one ever asks a question in a group of that size, and even if they could, no one else would hear the question! However, smaller groups can sustain a meaningful level of interaction, and often in FE classes, the sum can definitely be greater than the parts.

Dr Ashraf is focusing his time on smaller group tutorials, and will be using a course blog to respond to questions from students. His students can sms questions, and Dr Ashraf will then make the answers available on the course blog. In that way, over time, a ‘frequently asked questions’ list will no doubt emerge, and that can then drive re-drafting of the lecture material. One wonders if the course blogs include any tag cloud features that will promote common questions up the list.

• Dr Ashraf’s departmental page at the University of Bradford
• BBC story
• Alas, no link to the teaching blog appears to be available